Natural occurrence of entomopathogenic nematodes (Rhabditida: Steinernematidae) on golf courses in eastern Canada

Nematology ◽  
2007 ◽  
Vol 9 (3) ◽  
pp. 325-332 ◽  
Author(s):  
Julie Dionne ◽  
Guy Bélair ◽  
S. Patricia Stock ◽  
Louis Simard ◽  
Hervé Mauléon

AbstractA survey of entomopathogenic nematodes from 38 golf courses was conducted in different climatic areas of Ontario and Québec provinces, Canada, during autumn 2002 and 2003. Soil samples were collected on golf course greens, fairways and roughs. Entomopathogenic nematodes were isolated from soil using wax moth (Galleria mellonella) and carrot weevil (Listronotus oregonensis) larvae as bait. Of the 436 samples (218 sites), 11 contained entomopathogenic nematodes for this study. All entomopathogenic nematode-positive samples were isolated from roughs. Isolates were characterised using DNA satellite probes and 28S rDNA sequence data. Both methods confirmed the identities of nematode isolates as Steinernema carpocapsae, S. feltiae and S. kraussei.

Zootaxa ◽  
2007 ◽  
Vol 1461 (1) ◽  
pp. 25-37 ◽  
Author(s):  
SERGEY A. BELOKOBYLSKIJ ◽  
ALEJANDRO ZALDIVAR-RIVERÓN ◽  
VIRGINIA LEÓN-REGAGNON ◽  
DONALD L.J. QUICKE

A new genus and species of Lysitermini, Atritermus pedestris Belokobylskij, Zaldivar-Riverón & Quicke, are described from Madagascar. The taxonomic placement of the new genus within Lysiterminae is discussed based on a phylogenetic analysis using 28S rDNA gene sequences. A key to world genera of Lysitermini is provided.Un nuevo género y especie de Lysitermini, Atritermus pedestris Belokobylskij, Zaldivar-Riverón & Quicke, son descritos para Madagascar. La ubicación taxonómica del nuevo género dentro de Lysiterminae es discutida con base en un análisis filogenético usando secuencias del gen ribosomal 28S. Se presenta una clave para los géneros de Lysitermini del mundo.


Nematology ◽  
2008 ◽  
Vol 10 (4) ◽  
pp. 561-574 ◽  
Author(s):  
Juan Carlos López-Núñez ◽  
Kathryn Plichta ◽  
Carmenza E. Góngora-Botero ◽  
S. Patricia Stock

Abstract A new entomopathogenic nematode, Steinernema colombiense n. sp., is described from Colombia. Morphological, molecular (28S and ITS rDNA sequence data) and cross-hybridisation studies were used for diagnostics and identification purposes. In addition, 28S and ITS rDNA sequence data were used to assess evolutionary relationships of the new species with other Steinernema spp. Morphological diagnostic features for S. colombiense n. sp. include morphometric features of the third-stage infective juvenile, including body length of 636 (549-732) μm, narrow body diam. (31 (22-36) μm), position of the excretory pore (35 (31-40) μm), tail length (41 (32-53) μm), D% = 29 (25-33) and E% = 205 (138-284). In addition, males of first and second generations are characterised by the morphology of the spicules and gubernaculum, the number and arrangement of the genital papillae and the excretory pore position (at 67 (56-76) and 54 (46-63) μm, for first and second generations, respectively). In addition to these traits, 28S and ITS rDNA sequences analyses both showed this species to be a distinct and unique entity.


1997 ◽  
Vol 71 (3) ◽  
pp. 197-202 ◽  
Author(s):  
D.A. Bohan ◽  
W.M. Hominick

AbstractAn infection experiment was conducted to assess the change in the proportions of Steinernema feltiae Filipjev (Site 76 strain) infective juveniles becoming male or female on exposure to the test host Galleria mellonella L. Using a mathematical model for the infection interaction, the per capita probability of penetration per unit time (transmission coefficient), for those juveniles becoming male or female, and the magnitude of the male and female classes in the infective juvenile pool were estimated. The results show that S. feltiae infective juveniles which subsequently become female have a greater probability of invasion into test hosts than their male counterparts, which leads to markedly female biased sex ratios during the initial stages of the infection interaction. As the infection progresses, however, it was found that the sex ratio became balanced. This was because the underlying sex ratio in the infective stage pool was balanced. The implications of this dynamism in the sex ratio of the entomopathogenic nematodes are discussed with respect to the infection interaction, transmission and the likely environment in which the infective juveniles reside.


MycoKeys ◽  
2018 ◽  
Vol 41 ◽  
pp. 51-63 ◽  
Author(s):  
M. Ebinghaus ◽  
D. Begerow

Two new rust species, Raveneliapiepenbringiae and R.hernandezii (Pucciniales) on Senegalia spp. (Fabaceae) are described from the Neotropics (Panama, Costa Rica). A key to the species on neotropical Senegalia spp. is provided. Molecular phylogenetic analyses based on 28S rDNA sequence data suggest that the representatives of Senegalia rusts distributed in the neotropics evolved independently from species known from South Africa. This is further supported by the teliospore morphology, which is characterised by uniseriate cysts in the neotropical Senegalia rusts and contrasting multiseriate cysts in the paleotropic Ravenelia species that infect this host genus.


Nematology ◽  
2003 ◽  
Vol 5 (4) ◽  
pp. 601-608 ◽  
Author(s):  
G. Christopher Cutler ◽  
John Webster

Abstract The effect of plant roots on the host-finding ability of three isolates of entomopathogenic nematodes (EPN), Heterorhabditis bacteriophora D-H-Da1, Steinernema sp. Dongrae and Steinernema sp. BJ was studied. In Petri dish experiments the overall response of the infective juveniles (IJ) of these isolates differed from one another, but all were attracted to a Galleria mellonella larva and to a tomato seedling when either of these targets was presented with a blank control. The BJ and D-H-Da1 IJ aggregated more around a tomato root than a G. mellonella larva when these targets were presented separately, but showed no preference for a G. mellonella-tomato seedling combination over a blank control. Dongrae IJ showed no preference for a G. mellonella larva or tomato seedling when each was presented simultaneously in the same Petri dish. In experiments in pots of soil, plant roots did not affect the host-finding ability of Dongrae IJ. In contrast, compared to control pots with no roots, roots of bean plants hindered the ability of BJ IJ to infect a G. mellonella larva, but tomato roots increased host-finding by D-H-Da1 IJ. Roots of certain plant species modify the host-finding ability of EPN, but the extent and direction of the response varied with the EPN applied.


2004 ◽  
Vol 108 (10) ◽  
pp. 1119-1142 ◽  
Author(s):  
Dania García ◽  
Alberto M. Stchigel ◽  
José Cano ◽  
Josep Guarro ◽  
David L. Hawksworth

2017 ◽  
Vol 92 (1) ◽  
pp. 100-108 ◽  
Author(s):  
T.H. Cribb ◽  
N.Q.-X. Wee ◽  
R.A. Bray ◽  
S.C. Cutmore

AbstractWe describe Monorchis lewisi n. sp. (Monorchiidae) from the surf bream, Acanthopagrus australis (Günther, 1859) (Sparidae), in Moreton Bay, eastern Australia. The new species differs from most existing species of Monorchis Monticelli, 1893 in its possession of an elongate I-shaped excretory vesicle, and from other congeners in the relative configuration of the gut and suckers. Ovipusillus mayu Dove & Cribb, 1998 is re-reported from Gnathanodon speciosus (Forsskål, 1775) (Carangidae) from Moreton Bay. We report new second internal transcribed spacer (ITS2) and 28S rDNA sequence data for both species. Bayesian inference and Maximum Likelihood analyses of the 28S rDNA dataset suggest that existing subfamily and genus concepts within the family require substantial revision.


Parasitology ◽  
2007 ◽  
Vol 134 (6) ◽  
pp. 889-898 ◽  
Author(s):  
J. M. CHRISTEN ◽  
J. F. CAMPBELL ◽  
E. E. LEWIS ◽  
D. I. SHAPIRO-ILAN ◽  
S. B. RAMASWAMY

SUMMARYPotential hosts for infective juveniles of entomopathogenic nematodes can vary considerably in quality based on the characteristics of the host species/stage, physiological status (e.g. stress, feeding on toxins), and infection status (heterospecific or conspecific infection). In this study, we investigated responses of the entomopathogenic nematodeSteinernema riobraveto hosts (Galleria mellonellaorTenebrio molitor) that were previously parasitized with conspecifics or injected with the nematode-symbiotic bacterium,Xenorhabdussp., to determine if there is a preference for previously parasitized/injected hosts and when this preference might occur. In no-choice bioassays, the number of juveniles infecting both host species decreased with increasing time post-infection. However, infective juveniles continued to infect previously parasitized hosts up to 72 h. Significant preference was exhibited byS. riobravefor 24 h post-infectionG. mellonellalarvae over uninfected, and by 24 h post-injectionG.mellonellalarvae over 48 h post-injection larvae. No significant preference was exhibited byS. riobraveforT. molitorhosts previously parasitized with conspecifics or those injected with bacteria in any treatment combination. Such preference for, or continued infection of parasitized insects, has the potential to impact nematode efficacy.


2007 ◽  
Vol 85 (9) ◽  
pp. 873-882 ◽  
Author(s):  
Jinx Campbell ◽  
Astrid Ferrer ◽  
Huzefa A. Raja ◽  
Somsak Sivichai ◽  
Carol A. Shearer

Jahnulales is an order of freshwater, lignicolous, bitunicate ascomycetes characterized by wide (10–40 μm), brown, septate hyphae, stalked and (or) sessile ascomata, ascomal walls of 2–6 layers of large cells, and 1-septate ascospores. A variety of ascospore modifications are represented among the species in the order, including wall roughening, gelatinous sheaths, appendages and (or) pads, and apical caps or spines. To clarify generic boundaries and phylogenetic relationships within the Jahnulales and to assess the taxonomic significance of various morphological characters, a molecular study was carried out using 18S and 28S rDNA sequence data from 15 species representing the four genera in the order. In addition, Brachiosphaera tropicalis Nawawi and Xylomyces chlamydosporus Goos, R.D. Brooks & Lamore, two mitosporic species that co-occur with Jahnula Kirschst., species and have wide (>10 μm), brown, septate hyphae were included in the study to determine whether these species are members of this order. Maximum likelihood analyses confirmed the monophyly of the Jahnulales and resolved four clades. Two robustly supported clades comprise the genera Aliquandostipite Inderb. and Megalohypha A. Ferrer & Shearer. A third well-supported clade encompassed species of Brachiosphaera , Jahnula , and Xylomyces . The fourth clade contained isolates of the type species of the genus Jahnula, Jahnula aquatica (Plöttn. & Kirschst.) Kirschst., and two other members of this genus, but this clade was weakly supported. Our data suggest that the presence of very wide, brown, septate hyphae is an important character defining the Jahnulales. Based on molecular and morphological data, we propose the transfer of Jahnula siamensiae Sivichai & E.B.G. Jones and Patescospora separans Abdel-Wahab & El-Shar. to Aliquandostipite and emend the description of the Jahnulales.


Nematology ◽  
1999 ◽  
Vol 1 (7) ◽  
pp. 735-743 ◽  
Author(s):  
Parwinder S. Grewal ◽  
Edwin E. Lewis ◽  
Sudha Venkatachari

Abstract A possible mechanism of suppression of a plant-parasitic nematode Meloidogyne incognita by entomopathogenic nematodes is described. Heat-killed entomopathogenic nematodes Steinernema feltiae and S. riobrave temporarily suppressed penetration of the root-knot nematode M. incognita into tomato roots, but live nematodes had no effect. Infective juvenile M. incognita were repelled from all entomopathogenic nematode treatments that included their symbiotic bacteria. They were repelled by Galleria mellonella cadavers infected with S. carpocapsae, S. feltiae, and S. riobrave and from cell-free culture filtrates of the symbiotic bacteria Xenorhabdus nematophilus, X. bovienii, and Xenorhabdus sp. "R" from the three nematode species, respectively. Cell-free filtrates from all three Xenorhabdus spp. were toxic to M. incognita infective juveniles causing 98-100% mortality at 15% concentration. Cell-free filtrate of Xenorhabdus sp. "R" also reduced the hatch of M. incognita eggs. Application of formulated bacterial cell-free filtrates temporarily suppressed M. incognita penetration into tomato roots in a greenhouse trial. The short-term effects of cell-free bacterial filtrates, namely toxicity and repellency, were almost entirely due to ammonium. These results demonstrate allelopathic interactions between plant-parasitic nematodes, entomopathogenic nematodes and their symbiotic bacteria. The likely role of allelopathy in the suppression of plant-parasitic nematodes by innundative applications of entomopathogenic nematodes is discussed. Allelopathie: Ein moglicher Mechanismus zur Unterdruckung pflanzenparasitarer Nematoden durch insektenpathogene Nematoden - Es wird ein moglicher Mechanismus zur Unterdruckung des pflanzenparasitaren Nematoden Meloidogyne incognita durch insektenpathogene Nematoden beschrieben. Durch Hitze abgetotete insektenpathogene Nematoden Steinernema feltiae und S. riobrave underdruckten das Eindringen des Wurzelgallenalchens M. incognita in Tomatenwurzeln, lebende Nematoden hatten keine Wirkung. Infektionsjuvenile von M. incognita wurden von allen Behandlungen mit insektenpathogenen Nematoden abgestossen, die auch die symbiontischen Bakterien einschlossen. Sie wurden durch die Kadaver von Galleria mellonella abgestossen, die mit S. carpocapsae, S. feltiae und S. riobrave infiziert waren sowie durch zellfreie Kultursubstrate der symbiontischen Bakterien Xenorhabdus nematophilus, X. bovienii und Xenorhabdus sp. "R" aus den drei genannten Nematodenarten. Zellfreie Kultursubstrate von allen drei Xenorhabdus spp. waren giftig fur die Infektionsjuvenilen von M. incognita und verursachten in einer Konzentration von 15% Abtotungsraten von 98-100%. Zellfreie Kultursubstrate von Xenorhabdus sp. "R" vermiderten ausserdem das Schlupfen von M. incognita-Eiern. In einem Gewachshausversuch unterdruckten formulierte zellfreie Bakterienfiltrate vorubergehend das Eindringen von M. incognita in Tomatenwurzeln. Die Kurzzeitwirkungen von zellfreien Bakterien filtraten, namentlich Giftigkeit und Abstossung, waren nahezu ganz bedingt durch Ammoniak. Diese Ergebnisse zeigen das Vorhandensein von allelopathischen Wechselwirkungen zwischen pflanzenparasitaren Nematoden, insektenpathogenen Nematoden und deren symbiontischen Bakterien. Die wahrscheinliche Rolle von Allelopathie bei der Unterdruckung pflanzenparasitarer Nematoden durch eine Massenanwendung insektenpathogener Nematoden wird diskutiert.


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